Technical description and composition of the DEXP F42B7000T TV, type of panel and applicable modules. The composition of the modules.DEXP LED
Model: F42B7000T
Panel: K420WD7
T-CON: 6870C-0469A
LED driver (backlight): integrated into PSU
PWM LED driver: AP3041
Power Supply (PSU): K-PL-0A1 LYP03008A0 ZD-95 (G) F 465R10135DJB
PWM Power: OB5269CP
MOSFET Power: 10N80
MainBoard: MSD6308-T8E 4704-6308T8-A2233K01
IC MainBoard: MSD6308RTEC-SW, 9F2G08ABAEA
Technical Specifications F42B7000T
DEXP F42B7000T
General repair guidelines for TV LCD LED
Possible malfunctions
- The DEXP F42B7000T does not turn on. There are no signs of operability. The indicators on the front panel do not shine and do not blink, and the remote control and control buttons do not respond.
With such manifestations, in most cases, the LYP03008A0 power module is faulty. It is necessary to measure the output voltages in the secondary circuits, and in case of their absence, check the serviceability of the power switches of the converters and rectifier diodes for a short circuit.
In case of breakdowns in the secondary circuits, the converter can operate in a short circuit mode, and during a short circuit in the elements of the primary circuit, the mains fuse usually breaks.
The breakdown of Mos-Fet keys used in pulsed sources is often caused by malfunctions of other elements, for example, power supply, frequency-setting, damper ... as well as elements of the Negative Stabilization Feedback. PWM IC_Power may also cause a malfunction of the power switch of the converter and is checked by replacement.
- There is no image, there is sound, it is responding to the remote control. Or immediately after turning on for a second, the image may appear and immediately disappear.
In such cases, the most likely malfunction of the LED backlight elements. The reason for this may be a break in the LED circuit, or a problem in stabilizing their power supply.
When trying to detect a break in the LED lines, it should be taken into account that it is difficult to do this without disassembling the panel. For example, a current source is needed to open PN junctions connected in series.
- The TV does not turn on, the indicator indicates standby or operating mode, or blinks.
Repair or diagnostics of the motherboard MSD6308-T8E should begin by checking the stabilizers and power converters needed to power the chips and matrix. If necessary, update or replace the software (software).
If there is no reception of television channels, but the TV works properly from external devices, first of all you need to check the tuner tuner power supply and update the software. The pulses from the I2C bus must be controlled with an oscilloscope.
Once again, remind users! Attempts to self-repair a DEXP F42B7000T TV without the appropriate qualifications and necessary experience can lead to its complete non-repairability!
SCHEMATIC DIAGRAM / SERVICE MANUAL ------------------> LYP03008A0 Power supply
The appearance of the MainBoard MSD6308-T8E is shown in the figure below:MSD6308-T8E
MSD6308-T8E can be used in TVs:
DEXP F42B7000T (Panel K420WD7), DEXP F55B7000T (Panel K550WD7).
The appearance of the power supply
Main features of the DEXP F42B7000T device:
Installed matrix (LED-panel) K420WD7.
The matrix control uses the Timing Controller (T-CON) 6870C-0469A.
To power the backlight LEDs, a converter is used, combined with the power supply, controlled by the AP3041 PWM controller.
The necessary supply voltages for all nodes of the DEXP F42B7000T TV are generated by the K-PL-0A1 power module, or its analogs using OB5269CP chips and 10N80 type power switches.
MainBoard - the main board (motherboard) is an MSD6308-T8E module, using microchips MSD6308RTEC-SW, 9F2G08ABAEA and others.
DEXP F42B7000T TV with K420WD7 LCD, 42 "(107 cm) diagonal size in 16: 9 format. The required screen brightness of 300 cd / m² is provided by LED backlighting. Contrast - the ratio of maximum brightness to minimum is 1200: 1. In LCD - panels use direct LED backlighting - Direct LED. TV features include viewing programs and movies in high quality HD at a resolution of 1920x1080 pixels in the graphic resolution of the standard 1080p (Full HD). Input high-frequency or video signal al decoded into analog PAL system, SECAM, NTSC Image processing and the formation of the digital signal is in 480i standards, 480p, 576i, 576p, 720p, 1080i, 1080p Supported multimedia file formats:.. MP3, WMA, MPEG4, MKV, JPEG.
The power of the acoustic system of sound 20 W provide two speakers. The audio processing system NICAM STEREO is used.
The external interface (communication with other devices) is supported by standard input and output connectors: antenna input (RF), AV, component, VGA, HDMI x3, MHL, USB. An output for connecting headphones is provided. To connect a computer or laptop to this TV model, a VGA (D-Sub 15) connector is used on the TV case, this interface supports resolutions: 640x480, 800x600, 1024x768, 1280x1024, 1360x768, 1920x1080. A digital tuner is capable of receiving television channels in the DVB-T MPEG4, DVB-C, DVB-T2 standards.
Overall dimensions: with stand 980x620x250 mm,.
The mass of the TV: 8.22 kg.
Attention! The K420WD7 panel of a DEXP F42B7000T LED TV is an expensive and unreliable element.
Avoid any impact on the glass and pressure on the surface of the screen to avoid damage to the LED panel!
It is also unsafe to get liquid on the screen. Sometimes one drop is enough if it flows down the glass onto the cables so that the TV becomes unrepairable.